1. Field of the Invention
The present invention relates to a process and apparatus for lifting storage tanks.
2. Description of the Related Art
Large storage tanks, like the ones commonly found in refineries for storing oil, require maintenance from time to time. To access the bottom of the tank, the latter must be lifted off the supporting floor. This operation involves temporarily draining the tank. The time used for repairing the tank constitutes a waste of an expensive asset. Therefore, the lifting of these tanks must be accomplished in a safely and expeditious manner.
Applicant believes that the closest reference corresponds to U.S. Pat. No. 3,033,411 issued to J. Brucker et al on May 8, 1962. Brucker's apparatus involves the use of several hydraulic lifts adapted to exert an upward pressure on brackets carried by the outer periphery of the cylindrical wall, and a set of catenary suspension systems extending radially about the axis of the tank for the simultaneous lifting of the floating roof. The capacity of the jacks that would have to be used with this appparatus would be enormous specially if the tank is to be lifted a sufficient distance to allow the maintenance crew work on its bottom. Also, the outer surface of the peripheral wall of the tank need to have been provided with complementary means that cooperate with brackets provided with the jacks.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.